1. Technical Field
The present invention relates to a printing apparatus.
2. Related Art
Ink jet type printing apparatuses (line printers) that print an image on a medium by ejecting ink (UV ink), which is cured when the ink is irradiated with ultraviolet (UV) light, from plural heads aligned in a transport direction of the medium are known. In the printing apparatuses of this type, an image quality difference may be generated in an image to be printed depending on what color ink is ejected from which position of the head. For example, in JP-A-2004-268549, there is proposed an invention in which the quality of a printed image is improved by ejecting UV ink, which is not easily cured, from a head on a more upstream side in a transport direction and increasing an integrated light quantity of UV toward a downstream side in the transport direction. In addition, in JP-A-2007-276248, there is proposed an invention in which the quality of a printed image is improved by ejecting UV ink, which is not easily cured, from a head on a more upstream side in a transport direction and increasing an integrated light quantity of UV to be irradiated to the ink which is not easily cured in the transport process.
However, in JP-A-2004-268549 and JP-A-2007-276248, only the curability of the ink is considered and other properties are not considered. For example, phenomena such as solidification and aggregation occur in the UV ink in some cases, but the phenomena may also cause deterioration in quality of the printed image. That is, when an ink ejection order and an integrated light quantity of UV are determined by paying attention only to the curability of ink, it is difficult to print an image with sufficiently high quality.